Case study · SaaS platform

Construction cost estimator: from a WordPress plugin to a platform with an API and AI

Estimating logic moved out of a plugin into a platform with an API, matching the old version in 30 out of 30 test cases.

Industry: Construction
Duration: 06–09.2026
My role: CTO, architecture, team of 2–3 developers
Stack: AIAPI PlatformPostgreSQL 17Symfony 7.4Vue 3

01 · Problem

A cost estimator for an Australian construction company was locked inside a WordPress plugin. Without an API it could not be developed, integrated or changed safely.

02 · Solution

We designed a new domain model (13 entities) on Symfony 7.4, API Platform and PostgreSQL 17, with a Vue 3 front end. Before switching anything we built a golden test set from the old version and ran the new one in shadow mode alongside it. On top of that, an AI Plan Reader that reads building plans.

03 · Result

Results match the old version in 30 out of 30 golden-set cases. The AI Plan Reader reaches about 95% accuracy.

AnonymisationClient data anonymised. Company name, numbers and screenshots are published only with consent.

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